Chasing Australia's competitive 271 for six, built around skipper Michael Clarke's 117 and David Warner's 100, the islanders rode on a 179-run partnership for the opening wicket to overhaul the target with 34 balls to spare in what turned out to be a lop-sided contest.

Dilshan, who hit his 12th ODI century, and captain Mahela Jayawardene (80), rattled up the runs in just 27-odd overs which made the chase of 272 runs under lights easy.

The two produced the best batting partnership of the series and brought the Australians on to their knees, hitting boundaries at will and nearly always managing to strike in the gap.

The Australians were at a loss to stem the flow of runs and none of their bowlers, including otherwise efficient left-arm spinner Xavier Doherty, could bowl with economy.

The chase began good enough with Brett Lee conceding 12 runs in his first over but then there was a slice of luck in the second over when Jayawardene was caught behind for one, only for television reviews to reveal that the bowler Clint McKay had overstepped the bowling crease.

This was as close as Australians could have a sniff of a wicket for a long time as the two batsmen went after the bowlers, raising the first 50 off only 37 balls and bringing about the 100 in the 16th over.

The third final will be played at the same venue on Thursday.

Dilshan was the first one to reach his fifty off 56 balls with five fours while Jayawardene's half century arrived in as many balls, also with five fours.

The Lankans didn't slack at any stage and the hectic pace continued unabated, the 150 being raised off only 133 balls in the 22nd over.

Jayawardene finally fell for 80 to James Pattinson, leg before wicket as he shaped to play on the onside in the 28th over. The Sri Lankan captain faced only 76 balls and hit eight fours and a six.

Dilshan though wasn't going to let up at the other end and brought about his century in the 35th over though with a little bit of drama involved. He pulled Xavier Doherty, on 96, to square leg and believed it had crossed the ropes.

But Michael Hussey dived and saved the boundary, resulting in only two. But Dilshan had already celebrated the moment and his partner Kumar Sangakkara had gone up to him to congratulate. The century duly arrived two balls later, when he inside edged a cut past leg stump for two.

Dilshan finally departed in the 39th over, at 234 for 2, hitting Brett Lee straight to square leg fence. He still stayed long enough to raise 55 runs for the second wicket with Kumar Sangakkara (51 not out). In all, he batted for 119 balls and hit 10 fours.

Earlier, Clarke and Warner struck a century each to power Australia to 271 for six.

Warner, who just managed to get fit on time for the game, showed no signs of any groin injury during his 100-run knock on Tuesday and registered his second successive century after his 163 in the first final on Sunday.

Warner was complemented well by his captain Clarke (117), who scored a century after a gap of nearly a year. He scored his last ton in ODIs against Bangladesh in April last year.

The duo shared stitched together 184 runs for the third wicket to lay the foundation for Australia's total.

Both Warner and Clarke were intent to play waiting game and showed immense patience to consolidate Australia's innings after the hosts lost their first two wickets for 56 runs.

By his reputation, Warner played a very slow innings today, as he took 140 balls for his century with the help of four fours and a lone six.

On the other hand, Clarke’s innings was complete contrast as his 117 came off 91 balls with five fours and four sixes.

After laying the foundation, Warner and Clarke opened up towards the end as Australia amassed 62 runs of the last seven overs. The mayhem started in the 44th over of Ferveez Maharoof, which yielded 23 runs with a sequence of 6,4,6 and 4 coming from Clarke's bat.

While Clarke clipped Nuwan Kulasekara behind square leg in the 44th over for a single to complete his century in 81 balls, Warner reached the three figure mark an over later driving Lasith Malinga for a single.

But soon after completing his ton, Warner departed in the same over, held in the deep by Dilshan.

Opting to bat Australia lost Matthew Wade (14),bowled by off-spinner Tillakaratne Dilshan in the fifth over. New man in Shane Watson took 34 balls for his 15 before he was run-out in the 16th over, with Australia's scoreboard reading 56 for two.

From there on, it was Australia all the way, as Warner and Clarke joined hand to resurrect the innings with the 184-run third-wicket stand. The hosts did not try to force the issue in the powerplays also.

The first 10 mandatory powerplay overs produced 39 runs; the five overs of bowling powerplay between 16-20 overs yielded 28 runs and the batting powerplay between 32-36th over were worth 37 runs.

Clarke was the busier of the two, needing only 52 balls for his fifty while Warner reached his own off 69 balls.

Sri Lanka were uncharacteristically poor in the field with at least five catches put down, two of them by Herath.

Malinga was the pick of Sri Lanka bowlers, picking up three wickets for just 40 runs from his 10 overs.